CODEWITHSUNDEEP
awksed
IT-DONG
IT-DONG

Reputation: 41

Replace empty fields in tab separated file with "0"

Say I have a data file with rows like a^I^I^I^I^I^I^Ib^Ic, which is separated by ^I (means a tab).

Now, I want to change the empty value of each column into 0, so the result should be like: a^I0^I0^I0^I0^I0^I0^Ib^Ic.

How can I achieve it with only one sed command?

Upvotes: 0

Views: 2415

Answers (4)

SLePort
SLePort

Reputation: 15461

With GNU sed:

sed ':a;s/\t\(\t\|$\)/\t0\1/;ta' file

Replace all \t followed by \t or end of line with \t0.

Upvotes: 1

Ed Morton
Ed Morton

Reputation: 203645

$ awk '{while(gsub(/\t\t/,"\t0\t"));} 1' file
a       0       0       0       0       0       0       b       c

Upvotes: 0

karakfa
karakfa

Reputation: 67507

another awk

$ awk -v RS='\t' -v ORS='\t' '$0==""{$0=0}1'

or with BEGIN block

$ awk 'BEGIN{RS=ORS="\t"} $0==""{$0=0}1'

Upvotes: 0

Tom Fenech
Tom Fenech

Reputation: 74625

This is easier to do using a tool with support for look-ahead:

perl -pe 's/\t(?=\t)/\t0/g' file

This puts a "0" in between any pair of tab characters. The look-ahead is useful as it matches the second tab without consuming it, so it can be used in the next match.

Here's a way you could do it using awk:

awk -F'\t' -v OFS='\t' '{ for (i = 1; i <= NF; ++i) sub(/^$/, 0, $i) } 1' file

This loops through all the fields, substituting all empty ones with a 0.

Upvotes: 1

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